THE FUTURE HOUSE

Wairarapa Times-Age, 23 September 1938, Page 7

THE FUTURE HOUSE

USE OF PLYWOOD. Recent satisfactory experiments with plywood for houses in the United States of America have an interest for New Zealand which has plenty of timber suitable for that purpose. The development of new structural systems with plywood may prove to be one which will effect a major change in the design of smaller buildings (states Oscar Fisher, in the American “Architectural Record”). Most of the great forward movements in design were given their initial impetus by application of a new structural principle or material. It is important to recognise, however, that those innovations which were basically structural had a decisive and enduring influence upon design. Today any new material or method of construction which proves practical and economical for low-cost housing is certain of widespread use. A review of the recently developed structural systems with plywood should indicate useful applications to the designer and suggest further fields for fruitful experiment. Examples of plywood made in Egypt 3500 years ago still exist in good condition; but until recently, when the resinous binders ,were perfected, it could not be satisfactorily used on the exterior. The resinous binders made plywood waterproof, shrinkproof, checkproof, verminproof, fire-retard-ent, and prevalent delamination plywood is the strongest known material per unit of weight. Combining structural strength with a satisfactory surface for finish, easy to cut, light to handle, and adaptable to a variety of uses, its potentialities are only beginning to be explored. Much has been made of modular design, and suggestions on size range from the two-by-four to the two-room unit. Here is a material which is adapted for use in modules which make fabrication relatively simple, and yet are small enough for erection by one workman. Large, simple surfaces are at the disposal of the designer at a low cost with a workable material. Plywood used in place of other materials —e.g., sheathing, sub-flooring, plaster, etc., in large units —tends to reduce labour costs.

A method for prefabrication of large structural wall, floor, and roof units is the most important recent advance in the use of plywood. These units lend themselves equally well to factory or site fabrication. Various methods have been developed, all of them employing the basic ideas suggested by the Forest Products Laboratory. The units are formed by the application of plywood to both sides of an inner structural frame. A unit of great strength is produced by using plywood in compression and tension in the same members. In floor units this forms a box girder which will deflect only one-fourth as much as the joists acting alone. Wall units have been made with a light structural frame which tested as a beam to failure at 2001 b per square foot. A 60-mile wind has a pressure of 121 b per square foot. These units are superior to most other prefabricated systems proposed for residential construction, because they do not create the difficult problem of joining dissimilar materials.